1. Field of the Invention
The present invention relates to a solids incineration process and system, and more particularly, to such a process and system wherein the combustion gases produced are vented to the atmosphere with minimum pollution.
2. Brief Description of the Prior Art
The incineration of solids such as municipal solid refuse must be carried out in a system whereby the gaseous products of combustion are cooled and purified before being released to the atmosphere. In addition, the ash produced must be neutralized before being disposed of.
A commonly utilized system of the type described above includes a primary solids combustor such as a rotary kiln wherein the solids are combusted to produce combustion gases and ash. Gravity-separable ash from the primary combustor is conducted to an ash quench chamber wherein it is quenched and neutralized. The resulting neutralized wet ash is removed from the quench chamber and disposed of. The gaseous products of combustion exiting the primary combustor flow through a secondary combustion chamber wherein additional combustion takes place. The hot combustion gases are then conducted to a boiler or quench vessel wherein heat is removed therefrom followed by being conducted to a wet scrubber. In the web scrubber the combustion gases are contacted with a basic aqueous solution to remove fly ash, water soluble gases and other impurities therefrom, and the resulting cooled, purified gases are released to the atmosphere.
Heretofore, the spent scrubber liquid or blowdown from the wet scrubber has been separably disposed of and the quench liquid utilized for quenching the ash from the primary solids combustor has been from an independent source. By the present invention an improved process and system are provided whereby the spent scrubber liquid is utilized as at least a portion of the ash quench liquid.